Field of the Invention
This invention relates to a device for deflecting light. More particularly, this invention relates to a device for deflecting a laser light beam or other stimulating light employed for example in a radiation image information recording and read-out system for reading out the image information, and by means of which the angle of deflection can be set or adjusted with a very high level of precision.
Description of the Prior Art
It is known that when certain fluorescent substances are subjected to radiation (such as X-irradiation, .alpha. rays, .beta. rays, .gamma. rays, ultraviolet rays or the like) part of the radiation energy is stored in the fluorescent substance, and that when this fluorescent substance is then exposed to a stimulating ray, for example of visible light, the fluorescent substance emits light in proportion to the stored energy. Such substances are termed storage fluorescent substances.
The present applicant has already proposed (i.e. in Japanese unexamined patent application Nos. 55 (1980)-12429 and No. 56 (1981)-11395, etc.) a radiation image data recording and read-out system utilizing this storage fluorescent substance, wherein radiation image information such as of a human body is first recorded on a sheet provided with the storage fluorescent substance, and the sheet is then scanned with a stimulating light, such as laser light, to produce light emittance which is read out photoelectrically to obtain image signals which are output as visible images on a recording medium such as photosensitive materials, a CRT, or the like.
As the stimulating light used to scan a sheet provided with the storage fluorescent substance and on which the radiation image information is recorded, attempts have been made to employ a composite of a plurality of laser beams and utilize this composite laser beam to carry out high-speed scanning.
In order to form such a composite of laser beams it is necessary to have the light paths of the laser beams coincide. When using a composite laser beam as the stimulating light for scanning purposes in the above type of radiation image data recording and read-out system, it is particularly necessary that the light paths coincide to an extremely high level of precision, which means it is necessary to be able to carry out very fine angular adjustments to the light paths, in the order of a few microradians, for instance.
However, with conventional light deflection devices used to adjust light paths, especially devices which perform such deflection by employing mechanical means to angle mirrors and other such deflection elements to the required degree, it has been virtually impossible to adjust the angle of the light path to the said fineness of several microradians.